My first thought is some sort of tuile — easy to customize in both flavor and form, which rules; longer shelf life than you’d expect, also rules; but super fragile, which is generally not ideal, but in the case of OLLBs might work. It’s a very delicate concept, so a delicate material may be well suited. Tuiles also have the benefit of potentially being pure sugar, which would be good for a wide range of dietary restrictions.
Speaking of dietary restrictions — if dairy is on the table, the support of any sort of whipped cream will open up the possibilities for OLLBs to a huge degree. WC would also open up the possibilities for the base drink itself. Most critically, it would allow for flexibility in temperature. A tuile would sit gorgeously on a WC; without WC, it would sit decently well on an iced drink, but would disappoint on a hot drink.
I saw meringue in the replies and I concur. I’d also pitch marshmallow (flowers punched out of a thin sheet) as a possibility if gelatin is allowed. Either way, 1) a floral extract of choice can be added for aroma, 2) edible glitter mixed into cornstarch would prevent them from sticking together + add charm, and 3) a one-sided dip of chocolate would help to slow down their dissolution without preventing it entirely. These would likely suit either temperature equally well, and, if they’re lightweight enough, may even have the added bonus of negating the need for any WC at all. The downside is that they may be too "clunky," or too "candy-like" to execute the concept properly, bc it sounds like your vision for the OLLB is something quite dainty.
andulkaphoto
origamiaround
areudirty
